The effects of lactic acid fermentation on carotenoids from fruits of Cucurbita pepo L. var.giromontina are assessed using high performance liquid chromatography. As a consequence of exposure to an acidic pH, a differential degradation of carotenoids occurred. The most unstable carotenoid proved to be violaxanthin, but high percentages of degradation were recorded also for neoxanthin, lactucaxanthin, lutein and β-carotene – which proved to be the most stable carotenoid. As provitamin A activity of the studied matrix is mainly due to β-carotene, the degradation of this carotenoid was followed by a similar loss of provitamin A activity, which decreased from 53.32 µg RE/ g dry weight to 43.40 µg RE/ g dry weight.